Made in United States of America 



Reprinted from Physiological Reviews 

 Vol. V, No. 3, July, 1925 



111 



BLOOD PRESSURES IN MAN UNDER NORMAL AND 

 PATHOLOGICAL CONDITIONS 



J. A. MacWILLIAM 



The Physiological Laboratory of the University of Aberdeen, Scotland 



Long after accurate measurements of blood-pressure had been 

 practised on experimental animals, the study of blood-pressure in man 

 remained virtually a sealed book. Various early methods were tried 

 without reliable results; it was not until Riva Rocci (112) and somewhat 

 later L. Hill and Barnard (63) introduced the armlet method that 

 systolic pressure estimation became really practicable. Even after 

 this method had superseded the earlier attempts of Mosso, Gaertner, 

 Von Basch and others, many results were rendered more or less in- 

 accurate by imperfection in technique, too narrow armlets, etc., while 

 the reliance on systolic pressure alone gave very inadequate and often 

 misleading information as regards the state of the circulation. The 

 later development of diastolic pressure estimation, especially by the 

 auscultatory method, marked a great advance in the usefulness of the 

 study of blood pressure. The adoption of the standard breadth of 

 armlet or cuff as a result of Von Recklinghausen's (109) work was an 

 important step. 



As regards oscillatory methods the technique and the principles 

 involved have lost much of their interest and relevancy, since their 

 practical application has receded in importance in view of the develop- 

 ment and general adoption of the auscultatory method. The superi- 

 ority of the latter has become widely recognised, on the grounds of 

 simplicity, quickness and accuracy, as compared with the more cum- 

 brous apparatus and the more difficult and variable interpretation of 

 the oscillatory records, different readings of pressure often being made 

 from the same records by different observers of considerable experience 

 or even by the same observers at different times — difficulties examined 

 by Melvin and Murray (97) and others. A good many workers using 

 oscillatory methods have found the Pachon oscillometer with its visual 

 indications preferable to the Erlanger apparatus with its graphic 

 records. The more recent Pachon apparatus has a Gallavardin armlet 



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